We are extremely excited to present AR's 1M 3" Hi-Flo catless downpipes! The only TRUE 3" downpipes currently on the market! In addition to an intoxicating and exotic sound, these downpipes add significant power and virtually eliminate turbo lag, making the fabled N54 engine even more responsive!

Our Hi-Flo 3" Catless Downpipes Feature:

* The only TRUE 3" catless downpipes currently on the market! 3" tubing until cat-back flange - all systems currently on the market reduce to 2.5" much closer to the turbocharger.

* Available with a 2000Ã?Â° F ceramic coating. Coatings come with a 3 year warranty against corrosion and rust to original owner.

* Lifetime warranty against any manufacturing defects given to original owner.

* We do NOT grind/polish our welds as some other manufacturers do. Grinding welds compromises the strength of the weld, and can lead to weld failure - especially critical in applications exposed to temperatures in excess of 1200Â°F. Such temperatures will also rapidly deteriorate the polished finish.

Guys, there are a lot of people like me who are hesitant about the catless downpipes despite the fact that they should be giving best power gains, sound and especially response compared to other sections. This is not only because they will give you codes that need to erased, related warranty issue etc. but also they may give us other headaches (gas smell maybe?). But the biggest hesitance comes from the mid pipe option; I think lots of 1M owners think about an upgrade to a better exhaust but then ask themselves if a full system with aftermarket dps would be too much (too much install work, code trouble, smell, loudness etc.). So the question I am asking is does it really worth the trouble or a good rear muffler plus catless mids would be close enough in terms of response, feel, sound and power. Especially in comparison to dp + muffler set up like Evolve offers? In short, what is the way to go with optimum result and minimum trouble and why? Catless dp + oem mids + new muffler or oem dps + catless mids + new muffler. Or yet another option: catless dps + catless mids but oem muffler? Can people with first hand experience share their thoughts about this?

I am interested in this problem too, and have thought that most of the restriction is in the DP and then MP, not so much aft of the mid pipe. So figured most effective for power and some reasonable noise would be to keep stock "muffler" and get rid of both cats, tho assumes a tune to take care of CEL and to access the increased potential power. Anyone tried this approach?

Guys, there are a lot of people like me who are hesitant about the catless downpipes despite the fact that they should be giving best power gains, sound and especially response compared to other sections. This is not only because they will give you codes that need to erased, related warranty issue etc. but also they may give us other headaches (gas smell maybe?). But the biggest hesitance comes from the mid pipe option; I think lots of 1M owners think about an upgrade to a better exhaust but then ask themselves if a full system with aftermarket dps would be too much (too much install work, code trouble, smell, loudness etc.). So the question I am asking is does it really worth the trouble or a good rear muffler plus catless mids would be close enough in terms of response, feel, sound and power. Especially in comparison to dp + muffler set up like Evolve offers? In short, what is the way to go with optimum result and minimum trouble and why? Catless dp + oem mids + new muffler or oem dps + catless mids + new muffler. Or yet another option: catless dps + catless mids but oem muffler? Can people with first hand experience share their thoughts about this?

For the best power output and less strain on the turbos, especially with stage 2 software flashes, catless DP's are part of the hardware requirements to make the desired power.

If the ultimate power is not your goal, stock DP's with intake, FMIC, cat back exhaust and stage 1 tune may be good enough for you.

I am interested in this problem too, and have thought that most of the restriction is in the DP and then MP, not so much aft of the mid pipe. So figured most effective for power and some reasonable noise would be to keep stock "muffler" and get rid of both cats, tho assumes a tune to take care of CEL and to access the increased potential power. Anyone tried this approach?

I am assuming that any BMW service can erase CEL in case we swap to catless dps and mids but keep the stock muffler, technically speaking. They won't do it because the cars are still in warranty period etc. Dilemma but could be solved by some good coder.

I really think that this AR dps + Maddad pipes with stock muffler could sound like hell plus give optimum gains in hp/torque/response.

Anything else that needed to be taken into account about dps? Gas smell maybe?

For the best power output and less strain on the turbos, especially with stage 2 software flashes, catless DP's are part of the hardware requirements to make the desired power.

If the ultimate power is not your goal, stock DP's with intake, FMIC, cat back exhaust and stage 1 tune may be good enough for you.

Thanks. Yes I am thinking about all of those plus charge pipe and midpipes but minus any kind of engine remapping. I mean before any new software I want to have a 1M just with upgraded supporting mods wherever it may be useful but the engine itself remains untouched. I call it "everything but flash"

I don't own a 1M, but am running catless Dp's, N55 mids and a Berk tech. Street Exhaust. Power gains were noticable and did not have the "gas smell" whatsoever. One thing I did do was install the BMS o2 Sims to avoid the codes related to the catless downpipes.

My maintenance is done by an "independent" shop here in Germany so I really don't worry on code issues. I also have a BT tool so I can scan and see if I have any issues.

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Quote from Ezeedee regarding car mods:
"you're only done when you sell the car "

I don't own a 1M, but am running catless Dp's, N55 mids and a Berk tech. Street Exhaust. Power gains were noticable and did not have the "gas smell" whatsoever. One thing I did do was install the BMS o2 Sims to avoid the codes related to the catless downpipes.

My maintenance is done by an "independent" shop here in Germany so I really don't worry on code issues. I also have a BT tool so I can scan and see if I have any issues.